1. Field of the Invention
The present invention relates to equipment used in material drilling and, more particularly, to such equipment that is used to introduce a drilling fluid, such as oil, water or air, into a rotating drill sleeve that holds a drill bit with fluid passageways.
2. Setting of the Invention
In the use of large size drill presses, a drill bit retention device has been developed called a drill sleeve. The drill sleeve is generally a single piece of metal with a tapered upper portion that includes a tapered bore into which is inserted a drill bit. The sizes of drill bits and drill sleeves vary, but usually have a uniform tapering designation, such as, for example, having a Morse 5-3 taper.
Since there are no moving parts within the typical drill sleeve, the drill sleeves have very long operational lives. However, a drilling improvement has become quite prevalent which tends to reduce the operational lives of the drill sleeves. This development is called fluid drilling or "oil-hole" drilling, wherein a horizontal hole is included within the lower portion of the drill sleeve to provide a fluid path from a concentric outer fluid plenum or single piece fluid inducer through the hole and into one or more vertical fluid passageways through the drill bit. The application of fluid, such as oil, water, air or combinations of these, at the point of contact of a material with the drill bit greatly increases the drilling efficiency.
A problem with such fluid inducers and drill sleeves is that the fluid inducer remains stationary in relation to the rapidly rotating drill press spindle, drill sleeve (which extends through the fluid inducer) and drill bit. Internal bearings and O-ring sealing elements in the fluid inducer must be changed, which causes a loss of time. Further, the sealing elements tend to wear grooves on the drill sleeve, thus destroying the fluid seal; therefore, the expensive drill sleeve must be discarded. Also, when the inducer is removed to change the 0-rings, the bearings are often damaged.
There exists a need for a fluid inducer and drill sleeve which when used together provides easy removal of bearing and sealing elements, and provides an improvement such that if a sealing element wears on the drill sleeve the drill sleeve does not have to be discarded.